High resolution structures of both the free FabE8 and bound FabE8-cytc will enable us to identify detailed differences between the two Fab structures to better understand the mechanism of antibody recognition and binding. Further, by comparing the cytochrome- c of the FabE8-cytc structure with the high resolution structure of native cytochrome- c, we will be able to identify the effects of the E8 antibody on cytochrome- c and its heme. From these studies, we will be able to evalutate how the E8 antibody interacts to its highly charged, heme-containing antigen cytochrome-c.